gxfb: add power management functionality

This adds the ability to suspend/resume the gxfb driver, which includes:
  - The addition of a Graphics Processor register table in gxfb.h, and
    associated GP handling.
  - Register and palette saving code; registers are stored in gxfb_par.
    A few MSR values are saved as well.
  - gx_powerup and gx_powerdown functions which restore/save registers and
    enable/disable graphic engines.
  - gxfb_suspend/gxfb_resume

Originally based on a patch by Jordan Crouse.

Signed-off-by: Andres Salomon <dilinger@debian.org>
Cc: Jordan Crouse <jordan.crouse@amd.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/video/geode/Makefile

@@ -5,5 +5,5 @@ obj-$(CONFIG_FB_GEODE_GX)  += gxfb.o
 obj-$(CONFIG_FB_GEODE_LX)  += lxfb.o
 
 gx1fb-objs := gx1fb_core.o display_gx1.o video_cs5530.o
-gxfb-objs  := gxfb_core.o display_gx.o video_gx.o
+gxfb-objs  := gxfb_core.o display_gx.o video_gx.o suspend_gx.o
 lxfb-objs  := lxfb_core.o lxfb_ops.o

drivers/video/geode/gxfb.h

@@ -13,10 +13,34 @@
 
 #include <linux/io.h>
 
+#define GP_REG_COUNT   (0x50 / 4)
+#define DC_REG_COUNT   (0x90 / 4)
+#define VP_REG_COUNT   (0x138 / 8)
+#define FP_REG_COUNT   (0x68 / 8)
+
+#define DC_PAL_COUNT   0x104
+
 struct gxfb_par {
 	int enable_crt;
 	void __iomem *dc_regs;
 	void __iomem *vid_regs;
+	void __iomem *gp_regs;
+#ifdef CONFIG_PM
+	int powered_down;
+
+	/* register state, for power management functionality */
+	struct {
+		uint64_t padsel;
+		uint64_t dotpll;
+	} msr;
+
+	uint32_t gp[GP_REG_COUNT];
+	uint32_t dc[DC_REG_COUNT];
+	uint64_t vp[VP_REG_COUNT];
+	uint64_t fp[FP_REG_COUNT];
+
+	uint32_t pal[DC_PAL_COUNT];
+#endif
 };
 
 unsigned int gx_frame_buffer_size(void);
@@ -29,6 +53,43 @@ void gx_set_dclk_frequency(struct fb_info *info);
 void gx_configure_display(struct fb_info *info);
 int gx_blank_display(struct fb_info *info, int blank_mode);
 
+#ifdef CONFIG_PM
+int gx_powerdown(struct fb_info *info);
+int gx_powerup(struct fb_info *info);
+#endif
+
+
+/* Graphics Processor registers (table 6-23 from the data book) */
+enum gp_registers {
+	GP_DST_OFFSET = 0,
+	GP_SRC_OFFSET,
+	GP_STRIDE,
+	GP_WID_HEIGHT,
+
+	GP_SRC_COLOR_FG,
+	GP_SRC_COLOR_BG,
+	GP_PAT_COLOR_0,
+	GP_PAT_COLOR_1,
+
+	GP_PAT_COLOR_2,
+	GP_PAT_COLOR_3,
+	GP_PAT_COLOR_4,
+	GP_PAT_COLOR_5,
+
+	GP_PAT_DATA_0,
+	GP_PAT_DATA_1,
+	GP_RASTER_MODE,
+	GP_VECTOR_MODE,
+
+	GP_BLT_MODE,
+	GP_BLT_STATUS,
+	GP_HST_SRC,
+	GP_BASE_OFFSET, /* 0x4c */
+};
+
+#define GP_BLT_STATUS_BLT_PENDING	(1 << 2)
+#define GP_BLT_STATUS_BLT_BUSY		(1 << 0)
+
 
 /* Display Controller registers (table 6-38 from the data book) */
 enum dc_registers {
@@ -238,6 +299,16 @@ enum fp_registers {
 
 /* register access functions */
 
+static inline uint32_t read_gp(struct gxfb_par *par, int reg)
+{
+	return readl(par->gp_regs + 4*reg);
+}
+
+static inline void write_gp(struct gxfb_par *par, int reg, uint32_t val)
+{
+	writel(val, par->gp_regs + 4*reg);
+}
+
 static inline uint32_t read_dc(struct gxfb_par *par, int reg)
 {
 	return readl(par->dc_regs + 4*reg);
@@ -248,7 +319,6 @@ static inline void write_dc(struct gxfb_par *par, int reg, uint32_t val)
 	writel(val, par->dc_regs + 4*reg);
 }
 
-
 static inline uint32_t read_vp(struct gxfb_par *par, int reg)
 {
 	return readl(par->vid_regs + 8*reg);

drivers/video/geode/gxfb_core.c

@@ -28,6 +28,7 @@
 #include <linux/slab.h>
 #include <linux/delay.h>
 #include <linux/fb.h>
+#include <linux/console.h>
 #include <linux/init.h>
 #include <linux/pci.h>
 #include <asm/geode.h>
@@ -222,6 +223,15 @@ static int __init gxfb_map_video_memory(struct fb_info *info, struct pci_dev *de
 	if (!par->dc_regs)
 		return -ENOMEM;
 
+	ret = pci_request_region(dev, 1, "gxfb (graphics processor)");
+	if (ret < 0)
+		return ret;
+	par->gp_regs = ioremap(pci_resource_start(dev, 1),
+	pci_resource_len(dev, 1));
+
+	if (!par->gp_regs)
+		return -ENOMEM;
+
 	ret = pci_request_region(dev, 0, "gxfb (framebuffer)");
 	if (ret < 0)
 		return ret;
@@ -295,6 +305,42 @@ static struct fb_info * __init gxfb_init_fbinfo(struct device *dev)
 	return info;
 }
 
+#ifdef CONFIG_PM
+static int gxfb_suspend(struct pci_dev *pdev, pm_message_t state)
+{
+	struct fb_info *info = pci_get_drvdata(pdev);
+
+	if (state.event == PM_EVENT_SUSPEND) {
+		acquire_console_sem();
+		gx_powerdown(info);
+		fb_set_suspend(info, 1);
+		release_console_sem();
+	}
+
+	/* there's no point in setting PCI states; we emulate PCI, so
+	 * we don't end up getting power savings anyways */
+
+	return 0;
+}
+
+static int gxfb_resume(struct pci_dev *pdev)
+{
+	struct fb_info *info = pci_get_drvdata(pdev);
+	int ret;
+
+	acquire_console_sem();
+	ret = gx_powerup(info);
+	if (ret) {
+		printk(KERN_ERR "gxfb:  power up failed!\n");
+		return ret;
+	}
+
+	fb_set_suspend(info, 0);
+	release_console_sem();
+	return 0;
+}
+#endif
+
 static int __init gxfb_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
 	struct gxfb_par *par;
@@ -357,6 +403,10 @@ static int __init gxfb_probe(struct pci_dev *pdev, const struct pci_device_id *i
 		iounmap(par->dc_regs);
 		pci_release_region(pdev, 2);
 	}
+	if (par->gp_regs) {
+		iounmap(par->gp_regs);
+		pci_release_region(pdev, 1);
+	}
 
 	if (info)
 		framebuffer_release(info);
@@ -379,6 +429,9 @@ static void gxfb_remove(struct pci_dev *pdev)
 	iounmap(par->dc_regs);
 	pci_release_region(pdev, 2);
 
+	iounmap(par->gp_regs);
+	pci_release_region(pdev, 1);
+
 	pci_set_drvdata(pdev, NULL);
 
 	framebuffer_release(info);
@@ -396,6 +449,10 @@ static struct pci_driver gxfb_driver = {
 	.id_table	= gxfb_id_table,
 	.probe		= gxfb_probe,
 	.remove		= gxfb_remove,
+#ifdef CONFIG_PM
+	.suspend	= gxfb_suspend,
+	.resume		= gxfb_resume,
+#endif
 };
 
 #ifndef MODULE